1. Field of the Invention:
The present invention relates to a process for producing a linear .alpha.-olefin, more particularly, to a process for producing a high-purity linear .alpha.-olefin.
2. Description of the Prior
A linear .alpha.-olefin is useful as a comonomer for modification of polyolefins or as a raw material for plasticizers and surface active agent. In particular, a linear .alpha.-olefin having 6 to 18 carbon atoms is used in general.
A linear .alpha.-olefin of this type is conventionally produced by the oligomerization of ethylene which is accomplished by the aid of a catalyst composed of titanium or zirconium halide and an organoaluminum compound.
It is known that, in a process for producing a linear .alpha.-olefin, it is effective to add to the catalyst a sulfur compound, phosphorus compound, or nitrogen compound as a third component, in order to improve the purity of the linear a-olefin. A particularly effective sulfur compound includes dimethyl disulfide, thiophene, and thiourea. However, there is a disadvantage of contaminating a part of said third component into the linear .alpha.-olefin, when the catalyst being incorporated with said third component is used.
In order to eliminate this disadvantage, the present inventors carried out serious research on the process for producing a high-purity .alpha.-olefin free of contaminant. As the result, it was found that a sufficient effect can be obtained by the use of a small amount of a specific alcohol in place of the sulfur compound as a third component. This finding led to the present invention.